/*!	 twirl.cpp
**	 Implementation of the "Twirl" layer
**
**	Copyright (c) 2002-2005 Robert B. Quattlebaum Jr., Adrian Bentley
**	Copyright (c) 2011-2013 Carlos López
**
**	This package is free software; you can redistribute it and/or
**	modify it under the terms of the GNU General Public License as
**	published by the Free Software Foundation; either version 2 of
**	the License, or (at your option) any later version.
**
**	This package is distributed in the hope that it will be useful,
**	but WITHOUT ANY WARRANTY; without even the implied warranty of
**	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
**	General Public License for more details.
**
*/

#ifdef USING_PCH
#	include "pch.h"
#else
#ifdef HAVE_CONFIG_H
#	include <config.h>
#endif

#include <synfig/localization.h>
#include <synfig/general.h>

#include <synfig/string.h>
#include <synfig/time.h>
#include <synfig/context.h>
#include <synfig/paramdesc.h>
#include <synfig/renddesc.h>
#include <synfig/surface.h>
#include <synfig/value.h>
#include <synfig/valuenode.h>
#include <synfig/transform.h>
#include "twirl.h"

#endif

using namespace std;
using namespace etl;
using namespace synfig;
using namespace modules;
using namespace lyr_std;

SYNFIG_LAYER_INIT(Twirl);
SYNFIG_LAYER_SET_NAME(Twirl, "twirl");
SYNFIG_LAYER_SET_LOCAL_NAME(Twirl, N_("Twirl"));
SYNFIG_LAYER_SET_CATEGORY(Twirl, N_("Distortions"));
SYNFIG_LAYER_SET_VERSION(Twirl, "0.1");
SYNFIG_LAYER_SET_CVS_ID(Twirl, "$Id$");

Twirl::Twirl():
    Layer_CompositeFork(1.0, Color::BLEND_STRAIGHT),
    param_center(ValueBase(Point(0, 0))),
    param_radius(ValueBase(Real(1.0))),
    param_rotations(ValueBase(Angle::zero())),
    param_distort_inside(ValueBase(true)),
    param_distort_outside(ValueBase(false))
{
    SET_INTERPOLATION_DEFAULTS();
    SET_STATIC_DEFAULTS();
}

bool
Twirl::set_param(const String & param, const ValueBase &value)
{
    IMPORT_VALUE(param_center);
    IMPORT_VALUE(param_radius);
    IMPORT_VALUE(param_rotations);
    IMPORT_VALUE(param_distort_inside);
    IMPORT_VALUE(param_distort_outside);

    return Layer_Composite::set_param(param, value);
}

ValueBase
Twirl::get_param(const String &param)const
{
    EXPORT_VALUE(param_center);
    EXPORT_VALUE(param_radius);
    EXPORT_VALUE(param_rotations);
    EXPORT_VALUE(param_distort_inside);
    EXPORT_VALUE(param_distort_outside);

    EXPORT_NAME();
    EXPORT_VERSION();

    return false;
}

Layer::Vocab
Twirl::get_param_vocab()const
{
    Layer::Vocab ret;

    ret.push_back(ParamDesc("center")
                  .set_local_name(_("Center"))
                  .set_description(_("Center of the circle"))
                 );

    ret.push_back(ParamDesc("radius")
                  .set_local_name(_("Radius"))
                  .set_description(_("This is the radius of the circle"))
                  .set_is_distance()
                  .set_origin("center")
                 );

    ret.push_back(ParamDesc("rotations")
                  .set_local_name(_("Rotations"))
                  .set_description(_("The number of rotations of the twirl effect"))
                  .set_origin("center")
                 );

    ret.push_back(ParamDesc("distort_inside")
                  .set_local_name(_("Distort Inside"))
                  .set_description(_("When checked, distorts inside the circle"))
                 );

    ret.push_back(ParamDesc("distort_outside")
                  .set_local_name(_("Distort Outside"))
                  .set_description(_("When checked, distorts outside the circle"))
                 );

    return ret;
}

Point
Twirl::distort(const Point &pos, bool reverse)const
{
    Point center = param_center.get(Point());
    Real radius = param_radius.get(Real());
    Angle rotations = param_rotations.get(Angle());
    bool distort_inside = param_distort_inside.get(bool());
    bool distort_outside = param_distort_outside.get(bool());

    Point centered(pos - center);
    Real mag(centered.mag());

    Angle a;

    if ((distort_inside || mag > radius) && (distort_outside || mag < radius)) {
        a = rotations * ((centered.mag() - radius) / radius);
    } else {
        return pos;
    }

    if (reverse)	{
        a = -a;
    }

    const Real sin(Angle::sin(a).get());
    const Real cos(Angle::cos(a).get());

    Point twirled;
    twirled[0] = cos * centered[0] - sin * centered[1];
    twirled[1] = sin * centered[0] + cos * centered[1];

    return twirled + center;
}

Layer::Handle
Twirl::hit_check(Context context, const Point &pos)const
{
    return context.hit_check(distort(pos));
}

Color
Twirl::get_color(Context context, const Point &pos)const
{
    return context.get_color(distort(pos));
}

CairoColor
Twirl::get_cairocolor(Context context, const Point &pos)const
{
    return context.get_cairocolor(distort(pos));
}

class lyr_std::Twirl_Trans : public Transform
{
    etl::handle<const Twirl> layer;
public:
    Twirl_Trans(const Twirl* x): Transform(x->get_guid()), layer(x) { }

    Vector perform(const Vector& x)const
    {
        return layer->distort(x, true);
    }

    Vector unperform(const Vector& x)const
    {
        return layer->distort(x, false);
    }

    String get_string()const
    {
        return "twirl";
    }
};
etl::handle<Transform>
Twirl::get_transform()const
{
    return new Twirl_Trans(this);
}

RendDesc
Twirl::get_sub_renddesc_vfunc(const RendDesc &renddesc) const
{
    RendDesc desc(renddesc);
    Real pw = desc.get_pw();
    Real ph = desc.get_ph();
    desc.set_tl(Vector(-10.0, -10.0));
    desc.set_br(Vector(10.0,  10.0));
    desc.set_wh(
        (int)approximate_ceil(fabs((desc.get_br()[0] - desc.get_tl()[0]) / pw)),
        (int)approximate_ceil(fabs((desc.get_br()[1] - desc.get_tl()[1]) / ph)));
    return desc;
}

rendering::Task::Handle
Twirl::build_rendering_task_vfunc(Context context) const
{
    return Layer::build_rendering_task_vfunc(context);
}